Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/drivers/mfd/ti_am335x_tscadc.c

  1 /*
  2  * TI Touch Screen / ADC MFD driver
  3  *
  4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License as
  8  * published by the Free Software Foundation version 2.
  9  *
 10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 11  * kind, whether express or implied; without even the implied warranty
 12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  */
 15 
 16 #include <linux/module.h>
 17 #include <linux/slab.h>
 18 #include <linux/err.h>
 19 #include <linux/io.h>
 20 #include <linux/clk.h>
 21 #include <linux/regmap.h>
 22 #include <linux/mfd/core.h>
 23 #include <linux/pm_runtime.h>
 24 #include <linux/of.h>
 25 #include <linux/of_device.h>
 26 #include <linux/sched.h>
 27 
 28 #include <linux/mfd/ti_am335x_tscadc.h>
 29 
 30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
 31 {
 32         unsigned int val;
 33 
 34         regmap_read(tsadc->regmap_tscadc, reg, &val);
 35         return val;
 36 }
 37 
 38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
 39                                         unsigned int val)
 40 {
 41         regmap_write(tsadc->regmap_tscadc, reg, val);
 42 }
 43 
 44 static const struct regmap_config tscadc_regmap_config = {
 45         .name = "ti_tscadc",
 46         .reg_bits = 32,
 47         .reg_stride = 4,
 48         .val_bits = 32,
 49 };
 50 
 51 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val)
 52 {
 53         unsigned long flags;
 54 
 55         spin_lock_irqsave(&tsadc->reg_lock, flags);
 56         tsadc->reg_se_cache |= val;
 57         if (tsadc->adc_waiting)
 58                 wake_up(&tsadc->reg_se_wait);
 59         else if (!tsadc->adc_in_use)
 60                 tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
 61 
 62         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
 63 }
 64 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
 65 
 66 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 67 {
 68         DEFINE_WAIT(wait);
 69         u32 reg;
 70 
 71         reg = tscadc_readl(tsadc, REG_ADCFSM);
 72         if (reg & SEQ_STATUS) {
 73                 tsadc->adc_waiting = true;
 74                 prepare_to_wait(&tsadc->reg_se_wait, &wait,
 75                                 TASK_UNINTERRUPTIBLE);
 76                 spin_unlock_irq(&tsadc->reg_lock);
 77 
 78                 schedule();
 79 
 80                 spin_lock_irq(&tsadc->reg_lock);
 81                 finish_wait(&tsadc->reg_se_wait, &wait);
 82 
 83                 /*
 84                  * Sequencer should either be idle or
 85                  * busy applying the charge step.
 86                  */
 87                 reg = tscadc_readl(tsadc, REG_ADCFSM);
 88                 WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
 89                 tsadc->adc_waiting = false;
 90         }
 91         tsadc->adc_in_use = true;
 92 }
 93 
 94 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
 95 {
 96         spin_lock_irq(&tsadc->reg_lock);
 97         am335x_tscadc_need_adc(tsadc);
 98 
 99         tscadc_writel(tsadc, REG_SE, val);
100         spin_unlock_irq(&tsadc->reg_lock);
101 }
102 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
103 
104 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc)
105 {
106         unsigned long flags;
107 
108         spin_lock_irqsave(&tsadc->reg_lock, flags);
109         tsadc->adc_in_use = false;
110         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
111         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
112 }
113 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
114 
115 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
116 {
117         unsigned long flags;
118 
119         spin_lock_irqsave(&tsadc->reg_lock, flags);
120         tsadc->reg_se_cache &= ~val;
121         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
122         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
123 }
124 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
125 
126 static void tscadc_idle_config(struct ti_tscadc_dev *config)
127 {
128         unsigned int idleconfig;
129 
130         idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
131                         STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
132 
133         tscadc_writel(config, REG_IDLECONFIG, idleconfig);
134 }
135 
136 static  int ti_tscadc_probe(struct platform_device *pdev)
137 {
138         struct ti_tscadc_dev    *tscadc;
139         struct resource         *res;
140         struct clk              *clk;
141         struct device_node      *node = pdev->dev.of_node;
142         struct mfd_cell         *cell;
143         struct property         *prop;
144         const __be32            *cur;
145         u32                     val;
146         int                     err, ctrl;
147         int                     clock_rate;
148         int                     tsc_wires = 0, adc_channels = 0, total_channels;
149         int                     readouts = 0;
150 
151         if (!pdev->dev.of_node) {
152                 dev_err(&pdev->dev, "Could not find valid DT data.\n");
153                 return -EINVAL;
154         }
155 
156         node = of_get_child_by_name(pdev->dev.of_node, "tsc");
157         of_property_read_u32(node, "ti,wires", &tsc_wires);
158         of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
159 
160         node = of_get_child_by_name(pdev->dev.of_node, "adc");
161         of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
162                 adc_channels++;
163                 if (val > 7) {
164                         dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
165                                         val);
166                         return -EINVAL;
167                 }
168         }
169         total_channels = tsc_wires + adc_channels;
170         if (total_channels > 8) {
171                 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
172                 return -EINVAL;
173         }
174         if (total_channels == 0) {
175                 dev_err(&pdev->dev, "Need atleast one channel.\n");
176                 return -EINVAL;
177         }
178 
179         if (readouts * 2 + 2 + adc_channels > 16) {
180                 dev_err(&pdev->dev, "Too many step configurations requested\n");
181                 return -EINVAL;
182         }
183 
184         /* Allocate memory for device */
185         tscadc = devm_kzalloc(&pdev->dev,
186                         sizeof(struct ti_tscadc_dev), GFP_KERNEL);
187         if (!tscadc) {
188                 dev_err(&pdev->dev, "failed to allocate memory.\n");
189                 return -ENOMEM;
190         }
191         tscadc->dev = &pdev->dev;
192 
193         err = platform_get_irq(pdev, 0);
194         if (err < 0) {
195                 dev_err(&pdev->dev, "no irq ID is specified.\n");
196                 goto ret;
197         } else
198                 tscadc->irq = err;
199 
200         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
201         tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
202         if (IS_ERR(tscadc->tscadc_base))
203                 return PTR_ERR(tscadc->tscadc_base);
204 
205         tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
206                         tscadc->tscadc_base, &tscadc_regmap_config);
207         if (IS_ERR(tscadc->regmap_tscadc)) {
208                 dev_err(&pdev->dev, "regmap init failed\n");
209                 err = PTR_ERR(tscadc->regmap_tscadc);
210                 goto ret;
211         }
212 
213         spin_lock_init(&tscadc->reg_lock);
214         init_waitqueue_head(&tscadc->reg_se_wait);
215 
216         pm_runtime_enable(&pdev->dev);
217         pm_runtime_get_sync(&pdev->dev);
218 
219         /*
220          * The TSC_ADC_Subsystem has 2 clock domains
221          * OCP_CLK and ADC_CLK.
222          * The ADC clock is expected to run at target of 3MHz,
223          * and expected to capture 12-bit data at a rate of 200 KSPS.
224          * The TSC_ADC_SS controller design assumes the OCP clock is
225          * at least 6x faster than the ADC clock.
226          */
227         clk = clk_get(&pdev->dev, "adc_tsc_fck");
228         if (IS_ERR(clk)) {
229                 dev_err(&pdev->dev, "failed to get TSC fck\n");
230                 err = PTR_ERR(clk);
231                 goto err_disable_clk;
232         }
233         clock_rate = clk_get_rate(clk);
234         clk_put(clk);
235         tscadc->clk_div = clock_rate / ADC_CLK;
236 
237         /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
238         tscadc->clk_div--;
239         tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
240 
241         /* Set the control register bits */
242         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
243         tscadc_writel(tscadc, REG_CTRL, ctrl);
244 
245         /* Set register bits for Idle Config Mode */
246         if (tsc_wires > 0) {
247                 tscadc->tsc_wires = tsc_wires;
248                 if (tsc_wires == 5)
249                         ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
250                 else
251                         ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
252                 tscadc_idle_config(tscadc);
253         }
254 
255         /* Enable the TSC module enable bit */
256         ctrl |= CNTRLREG_TSCSSENB;
257         tscadc_writel(tscadc, REG_CTRL, ctrl);
258 
259         tscadc->used_cells = 0;
260         tscadc->tsc_cell = -1;
261         tscadc->adc_cell = -1;
262 
263         /* TSC Cell */
264         if (tsc_wires > 0) {
265                 tscadc->tsc_cell = tscadc->used_cells;
266                 cell = &tscadc->cells[tscadc->used_cells++];
267                 cell->name = "TI-am335x-tsc";
268                 cell->of_compatible = "ti,am3359-tsc";
269                 cell->platform_data = &tscadc;
270                 cell->pdata_size = sizeof(tscadc);
271         }
272 
273         /* ADC Cell */
274         if (adc_channels > 0) {
275                 tscadc->adc_cell = tscadc->used_cells;
276                 cell = &tscadc->cells[tscadc->used_cells++];
277                 cell->name = "TI-am335x-adc";
278                 cell->of_compatible = "ti,am3359-adc";
279                 cell->platform_data = &tscadc;
280                 cell->pdata_size = sizeof(tscadc);
281         }
282 
283         err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
284                         tscadc->used_cells, NULL, 0, NULL);
285         if (err < 0)
286                 goto err_disable_clk;
287 
288         device_init_wakeup(&pdev->dev, true);
289         platform_set_drvdata(pdev, tscadc);
290         return 0;
291 
292 err_disable_clk:
293         pm_runtime_put_sync(&pdev->dev);
294         pm_runtime_disable(&pdev->dev);
295 ret:
296         return err;
297 }
298 
299 static int ti_tscadc_remove(struct platform_device *pdev)
300 {
301         struct ti_tscadc_dev    *tscadc = platform_get_drvdata(pdev);
302 
303         tscadc_writel(tscadc, REG_SE, 0x00);
304 
305         pm_runtime_put_sync(&pdev->dev);
306         pm_runtime_disable(&pdev->dev);
307 
308         mfd_remove_devices(tscadc->dev);
309 
310         return 0;
311 }
312 
313 #ifdef CONFIG_PM
314 static int tscadc_suspend(struct device *dev)
315 {
316         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
317 
318         tscadc_writel(tscadc_dev, REG_SE, 0x00);
319         pm_runtime_put_sync(dev);
320 
321         return 0;
322 }
323 
324 static int tscadc_resume(struct device *dev)
325 {
326         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
327         u32 ctrl;
328 
329         pm_runtime_get_sync(dev);
330 
331         /* context restore */
332         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
333         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
334 
335         if (tscadc_dev->tsc_cell != -1) {
336                 if (tscadc_dev->tsc_wires == 5)
337                         ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
338                 else
339                         ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
340                 tscadc_idle_config(tscadc_dev);
341         }
342         ctrl |= CNTRLREG_TSCSSENB;
343         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
344 
345         tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
346 
347         return 0;
348 }
349 
350 static const struct dev_pm_ops tscadc_pm_ops = {
351         .suspend = tscadc_suspend,
352         .resume = tscadc_resume,
353 };
354 #define TSCADC_PM_OPS (&tscadc_pm_ops)
355 #else
356 #define TSCADC_PM_OPS NULL
357 #endif
358 
359 static const struct of_device_id ti_tscadc_dt_ids[] = {
360         { .compatible = "ti,am3359-tscadc", },
361         { }
362 };
363 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
364 
365 static struct platform_driver ti_tscadc_driver = {
366         .driver = {
367                 .name   = "ti_am3359-tscadc",
368                 .pm     = TSCADC_PM_OPS,
369                 .of_match_table = ti_tscadc_dt_ids,
370         },
371         .probe  = ti_tscadc_probe,
372         .remove = ti_tscadc_remove,
373 
374 };
375 
376 module_platform_driver(ti_tscadc_driver);
377 
378 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
379 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
380 MODULE_LICENSE("GPL");
381 

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